The present invention relates to a baler and in particular but not exclusively to a baler for baling an agricultural crop. The invention also relates to a roller for use in a variable chamber round baler.
Round balers for agricultural produce are well known from for instance EP2269440 and U.S. Pat. No. 8,037,814.
These balers gather agricultural crop material from the ground with a pick up mechanism and, optionally after cutting the material, the material is forwarded to a bale chamber that compresses the material to form a round bale. After compression the bale is wrapped with binding material, for example netting, twine or film, to keep the material under pressure and to maintain its shape. After binding the bale is ejected from the bale chamber.
Balers can be of various types including fixed chamber balers that produce a bale of a fixed diameter, and variable chamber balers which can produce bales of different diameters. The variable chamber balers usually make use of a set of endless belts running over rollers as in the prior art mentioned above. This invention relates particularly but not exclusively to this latter type of baler.
A problem with these variable chamber balers is that the crop material to be compressed has a tendency in some conditions to wind around the rollers on which the belts are running and become entangled. This can also occur at the ends of the roller where the roller is attached to the side walls of the baler or to tensioning arms that keep the belts under tension.
The entangled crop material can cause a lot of friction and this can produce a lot of heat. The crop material can also penetrate through one or more of the seals that protect the bearing inside the roller. If the crop material penetrates through the seals and gets entangled in the bearing the material may in the end destroy the bearing.